Absorption refrigerating system



' Aug. 1, 1939.

R. s. NELSON ABSORPTION REFRIGERATING SYSTEM Filed Aug. 8, 193a ob attempts to econornine,

tailed. The weight at the wealr aqua flowing in.

a: rromthe boiler to the ab:

sorber is always less than the weight of the Patented Aug. 1, 1939 UNITED STATES PATENT OFFICE EJIGWQQW ABSORPTION REFRIGERATEQG SYSTEM Rudolph 8. Nelson, liarchmont, N. T., asslgnor to The Hoover lllompany, North wanton, @hio, a

corporation oi Ohio Application Ant gust t, lath, herial No. ll lflllt h lCllai.

This invention relates to continuous absorption refrigerating systems and more particularly to an analyzer and associated parts adapted to aid in the separation of refrigerant vapor from g the vapor of the absorption liquid used within such a system.

The use of analyzers in continuous absorption refrigerating systems are known. Example of their use in continuous absorption systems adaptm ed for household refrigerating systems are disclosed in the co-pending applications of Nelson, Serial No. 63,097 filed Feb. 10, 1936, and the application of Coons, Serial No. 31,676 filed May 25, 1936.

it It is an object of the present invention to provide an improved analyzer and to provide improved meansfor dividing absorption liquids leaving the absorber of the refrigerating systems into two streams, one of which enters the my analyzer at one level and another of which enters the analyzer at another level. a

It is another object of the invention to provide an improved analyzer system in which only part of the absorption liquid flowing from the absorber to the boiler is used in the analyzing action;

Other objects and advantages reside in certain novel features of the arrangement and the construction of parts as will be apparent from 30 the following description taken in connection with the accompanying drawing in which:

Figure 1 is a diagram of a continuous absorption refrigerating system with an analyzer shown partly in cross section incorporated therein and 35 illustrating onev embodiment of the present invention.

Figure 2 is an enlarged vertical cross-sectional view of a solution divider employed in the arrangement of Figure 1 and 40 Figure 3 is a horizontal cross-sectional view or the solution divider, the view being taken on the line 3-3 of Figure 2.

Many expedients have been proposed for utilizing the high grade heat energy contained in the 45 raw vapor expelled from the boiler of an absorption refrigerating system using three fluids. These errpedients have included analyzers, submerged analyzers, auiriliary boilers heated by the rectifiers andso forth. In spite oi the prior certain losses have enagiven unit or 1,

strong aqua flowing from the absorber to the boiler ding that interval at te by the quantity of refrigerant taken upin the absorber. Hence it is impossible to heat up the strong aqua flowing through the boiler to the boiler temperature even if a perfect solution heat exchanger were used, because the quantity of heat required to a heat up the strong aqua is greater than the quantity of heat available in the weak aqua flowing in the same interval of time. Thus the weal: aqua always enters the boiler or analyzer at a temperature below its boiling point and it must it be heated up to that boiling point by an addi tional expenditure of heat.

In the arrangement shown in Figure 1, means is provided for utilizing the heat contained in the vapor leaving the boiler for heating the W strong aqua. The system shown is of the type in which three fluids are employed, namely, an absorption liquid, a refrigerant and an inert gas. Water, ammonia, and nitrogen may be used, for example. at

The refrigerating system shown consists of a boiler designated B, a condenser C, an evaporator E and an absorber A, these parts being connected by various conduits to form the complete refrigerating system.

In the arrangement illustrated in Figure 1, it is intended that the absorption liquid be lifted upwardly in the absorber by means of a suitable pumping means so that no gas lift pump is employed. The refrigerant vapor and some of the 30 absorption liquid vapors generated in the boiler pass upwardly through the vertical pipe H which acts as both an analyzer and a rectifier, and then passes through the conduit l2 into the condenser C. The refrigerant condensing in the condenser 35 C flows through the conduit l3 into the evaporator where it evaporates into the inert gas and is conveyedinto the absorber.

The evaporator and the absorber may be connected by two inert gas conduits l4 and [5 which 40 may be in heat exchange relation, although this is not illustrated on the drawing.

Absorption liquid flows from the boiler B through the conduit It, which may be termed the outgoing circuit, into the bottom of the ab- 45 sorber. This flow may be by gravity, the liquid level standing in the pipe ll being sumciently high to be above the point of entrance of the conduit it intothe bottom or the absorber. lBy

some suitable pumping means such as an ordithnary centrifugal another known types of liquid v circulating devices, "the, absorption liquid may be caused to flow upwardly through the absorber and leave .thels ,r n'e hrough the small conduit it near the upper The absorption liquid leaving the absorber through the conduit I'l flows into a small solution dividingchamber l9 where it is divided into two streams, one of which flows through the conduit 20 and the other of which flows'through the conduit 2|. Conduits 20 and 2| constitute the return circuit for the strong absorbent medium. Both conduits 20 and 2| discharge into the vertical cylinder II, the conduit 2| being connected thereto at the higher level.

Either or both of the conduits 20 and 2| may be in heat exchange relation with a portion of the conduit [6. It is preferable, however, to have only the conduit 20 pass in heat exchange relation with the absorption liquid leaving the boiler. through the conduit I6 and this construction is illustrated on the drawing.

The solution divider within the cylinder or vessel l9 may consist of a pivot point or knife edge 22 which divides the vessel l9 into a left and right'hand chamber. Upon this, a tiltable dish 23 is pivoted. The dish 23 may be provided with a partition 24 which divides it into two cups as illustrated. The two cups may be of different volumes so as to proportion the solution in any desired way and may be weighted to maintain the proper balance. It will be seen that with the construction illustrated absorptionliquid dripping through the conduit ll falls in either the left. or right hand cup of the dish 23 depending upon its position. Upon the weight in the cup being suflicient the dish will tilt so that the other cup may be filled. In this way the solution may be carefully divided or proportioned. 1

Located within the vertical pipe I I are a number of baffle plates or other means for providing an extended surface as illustrated at 25. The pipe 2| is preferably connected above the baflie plates and the pipe 20 below the same.

If, now the solution divider within the vessel I9 is so constructed as to divide the two streams into a larger and a smaller one, the larger stream may be such that the wntity of heat required .to raise its temperature to the boiling point will be substantially that quantity available in the weak aqua flowing from the boiler through the conduit IS. A heat transfer of this exact quantity may thus be effected from the conduit l6 to the conduit 20. This stream may then enter the analyzer and the boiler but little additional heat will be required to generate the refrigerant therefrom.

The remainder of the strong aqua, that is, the smaller portion which flows through the conduit 2| may correspond roughly in heatcapacity to the heat capacity of the vapors leaving the boiler-analyzer assembly. If this smaller portion of the strong aqua does .not pass in heat exchange relation with the solution in the conduit l8, it may be brought directly from the absorber in heat exchange with the hot vapors in the analyzer. Heat exchange may then take place between the vapors and the strong aqua entering the analyzer and flowing down over the baflle plates 25 therein. The vapors within the analyzer should be brought into as intimate contact with the solution on the plates 25 as is possible and to this end either of the plates 25 or all of them may be located below the normal solution level within the boiler so that the best heat exchange possible may be obtained. Counterflow of liquid and gas, as illustrated in the construction of Figure 1 is also preferable.

The arrangement illustrated in Figure i does not show means for draining the evaporator but it will be obvious to those skilled in the art that any liquid which does not evaporate in the evaporator may be added to the absorption liquid flowing through the conduit 2| and thus supplied to the analyzer either through the conduit 2| or above the point of entrance of the conduit 2| in the analyzer to aid in the removal of absorption liquid vapors from the refrigerant vapors passing s upwardly therethrough.

By using an analyzer constructed in accordance with the present invention it may be possible to eliminate the rectifier entirely in some instances although in the arrangement shown the upper end of the vertical pipe may be provided with baffle plates inside or with heat radiating fins on the o utside to provide some rectifier action.

-While the arrangement illustrated in Figure l is of a known type of refrigerating systemin which an inert gas is used and in which the absorption liquid is caused to flow upwardly through the absorber, it is obvious that the present invention may be used in connection with other systems such as those in which no inert gas is employed or in which the absorption liquid flows downwardly through the absorber, any arrangement in which the solution leaving the absorber may be divided into two streams being all that is necessary to carry out the principles rator, and an absorber connected in circuit, said circuit including means for the circulation of absorption solution between said boiler .and said absorber, said circuit being characterized by the provision of means for delivering independent streams of absorption solution to said analyzer at spaced points therealong whereby the analyzing effect of said independent streams upon the fluids in said analyzer is distributed over different portions of said fluids.

2. An absorption refrigeration system comprising a boiler, an analyzer, a condenser, an evaporator, and an absorber connected in circuit, said rator, and an absorber connected in circuit, said circuit including means for the circulation of absorption solution between said boiler and said absorber, said circuit being characterized by the provision of means for dividing a stream of absorption solution into a plurality of independent streams, means for conducting one of said streams directly to said analyzer, means for preheating another of said streams, and means for delivering said preheated stream to said analyzer at a point spaced from the point of entrance of said one stream.

4. An absorption refrigeration system including a boiler-analyzer assembly, a condenser, an evaporator and an absorber connected in circuit, said system containing a refrigerant and an absorbent medium therefor and being so charged that the normal operating level of absorption solution in said assembly during the operation or the system is intermediate the upper and lower portions of said analyzer, said circuit being characterized by the provision of conduits for returning a plurality of streams of enriched solution from said absorber to said boiler-analyzer assembly, one of said conduits discharging thereinto at a point above the normal solution level and another conduit discharging thereinto at a point below the normal solution level.

5. An absorption refrigeration system as recited in claim 4 further characterized by the fact that said circuit is so arranged as to preheat one of the streams of enriched solution flowing to the boiler-analyzer assembly.

6. An absorption system having a boiler assembly, a condenser, an evaporator and an absorber connected in circuit, said circuit including an absorption solution circuit between said boiler assembly and said absorber, said absorption solution circuit being characterized by a plurality of return passageways for emiched solution flowing from the absorber to the boiler assembly and discharging into the latter at spaced points, and means in addition to the conduits required to form said return passageways operable to divide the enriched solution therebetween.

'7. An absorption system having a boiler assembly, a condenser, an evaporator and an absorber connected in circuit, said circuit including an absorption solution circuit between said boiler assembly and said absorber, said absorption solution circuit being characterized by a plurality of return passageways for enriched solution flowing from the absorber to the boiler assembly and discharging into the latter at spaced points, and means in addition to the conduits required to form said return passageways operable to divide the enriched solution therebetween, said dividing means being sealed within said system and arranged to divide the absorption solution into a plurality of streams oi pre-determined relative size.

8. An absorption system having a boileranalyzer assembly, a condenser, an evaporator and an absorber connected in circuit, said circuit including an absorption solution circuit between said boiler-analyzer assembly and said absorber, said circuit being characterized by the provision of means forming a plurality of return passageways for rich solution flowing from said absorber to spaced points in an upper portion of said boiler-analyzer assembly, and means in addition to the means necessary to form said return passageways sealed within said system and operable upon circulation of absorption solution in its circuit to-divide said solution into streams of predetermined size between said return passageways.

RUDOLPH S. NELSON. 

